The present invention relates to optical devices for detecting a magneto-optical signal and, particularly to an optical device having a novel optical element.
Optical devices, i.e., magneto-optical pickup portions of so-called magneto-optical disc drives use polarizing elements, such as a Wollaston polarizing prism and a polarizing beam splitter (PBS) to assemble optical assemblies in a hybrid fashion. Therefore, an overall arrangement of a magneto-optical pickup becomes complicated and large. Furthermore, optical layout of optical assemblies have to be set with high alignment accuracy.
In addition, each optical element is expensive and the magneto-optical pickup is difficult to be made inexpensive.